Production of menthol



Patented June 25, 1929.

UNITED STATES PATENT OFFICE.

WEI QTER SGHOELLER, OF BERLIN-WESTEND, AND-HANS JORDAN, OF BERLIN-STEGLITZ, GERMANY, ASSIGNORS TO THE FIRM: CHEMISCKE FABBIK AUF ACTIEN, VOBM. E.

SCHEBING., F BERLIN, GERMANY.

PRODUCTION OF 'MENTHOL.

NoDrawing. Application filed June 20, 1927, Serial No. 200,298, and 11! Germany June 29, 1928. a

Our invention refers to the production of alkyl isopropyl phenols and more especially menthol.

As disclosed in the copending application vfor patent of the United States Serial No.

280,290 filed of even date herewith by Hans "Jordan,'alkyl isopropylene phenol, such as 3-methyl-6-isopropylene phenol 01g on g CH: on can be obtained by heating the condensation products from a ketone, such as acetone, and an alkyl phenol, such as m-cresol and pcresol, respectively, to about 300 to 310 to effect decomposition, and subjectin the products of decomposition to fractiona distillation, preferably in vacuo.

We have now ascertained that by treating these products with hydrogen in the presence of a suitable hydrogenation catalyst so as to introduce eight atoms hydrogen, we are enabled to convert them into menthol and its isomers and homologues, being the corresponding phenols saturated in the side chain. L

. Ewample 1 3-methyl-6-isopropylene and, if desired,

. under pressure in the presence of a mixed catalyst containin Ni and another metal, such as Cu, Co,

e, and the like, either in reduced state or as carbonates, hydroxides, or the like, until eight hydrogen atoms have entered the combination. There is thus obtained menthol.

Example 2 4-methyl-6-isopropylene phenol is treated with hydrogen at 140160 C. and, if desired, under pressure in the presence of a mixed catalyst, containing Ni'and another metal, such as- Cu, Co, Fe, and the like, either in reduced state or as carbonates, hydroxides,

or the like, until eight hydrogen atoms have entered the combination. There is thus obtained l-methyl-G-isopropyl cyclo liexanol (1), this being the hitherto unknown p-lnenthol.

Various changes may be made in the details disclosed in the foregoing specification Without departing from the invention or sacrificing the advantages thereof.

lVe cla1m:-- l 1. The process of producing a menthol comprising acting on a methyl isopropylene OH H.CH(CH:)|

. H.0Hl

tures.

WALTER SCHOELLER. HANS JORDAN.

In testimony whereof we afiix our signa- 

